code: def test_sequential(self):
      num_episodes = 3
      steps_per_episode = 4
      env = test_envs.CountingEnv(steps_per_episode)
  
      for episode in range(num_episodes):
          step = 0
          time_step = env.reset()
          self.assertEqual(episode * 10 + step, time_step.observation)
          while not time_step.is_last():
              time_step = env.step(0)
              step += 1
              self.assertEqual(
                  episode * 10 + step, time_step.observation
              )
          self.assertEqual(
              episode * 10 + steps_per_episode, time_step.observation
          )
  
file_path: agents/tf_agents/environments/test_envs_test.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tf_agents.environments import test_envs
  from tf_agents.environments import utils
  from tf_agents.utils import test_utils
label_desc: Use image node_id 1 for calling the CountingEnvTest obj's underlying member method code with example usage: obj.test_sequential() without return types